battery

1[countable]a device that is placed inside a car engine, clock, radio, etc. and that produces the electricity that makes it workto change the batteriesa rechargeable batterybattery-powered/-operateda car batteryThe battery is dead (= it is no longer producing electricity).

2[countable]battery (of something)a large number of things or people of the same typeHe faced a battery of questions.a battery of reporters